CVE-2025-38078

In the Linux kernel, the following vulnerability has been resolved:

ALSA: pcm: Fix race of buffer access at PCM OSS layer

The PCM OSS layer tries to clear the buffer with the silence data at initialization (or reconfiguration) of a stream with the explicit call of sndpcmformatsetsilence() with runtime->dmaarea. But this may lead to a UAF because the accessed runtime->dmaarea might be freed concurrently, as it's performed outside the PCM ops.

For avoiding it, move the code into the PCM core and perform it inside the buffer access lock, so that it won't be changed during the operation.